The eco-guide to responsible drinking.

Wear Green, Drink Greenly

The eco-guide to responsible drinking.

Those who plan a night (or day) of hearty St. Patrick's Day drinking don't have to sacrifice their eco-consciences along with their motor skills. In March 2008, Brendan I. Koerner pub-crawled his way through the environmental virtues of bottled, canned, and draught beer. His findings are below.

Should your St. Patrick's Day pint come from a bottle or a can?

I've been gearing up for next week's St. Patrick's Day drink-a-thon. If I'm intent on being an environmentally correct lush, should I plan on quaffing my suds from bottles or cans?

That's a tough question to answer without knowing how far you live from your favorite brewery, as well as your brewery's stance on using recycled materials. If your chosen tipple is produced very close to home and your town has a robust recycling program, then glass bottles are probably the way to go. But if your preferred suds are brewed far away, by a company that's even mildly eco-aware, aluminum cans are the wiser choice.

Between the mine and the brewery's loading dock, at least, glass bottles are the clear winner. Aluminum is made from bauxite, which requires substantial, land-scarring effort to extract from the Earth; the United States imports virtually all of its bauxite from the likes of Australia, Guinea, and Jamaica, where mining operations have caused environmentalcontroversy. Glass, by contrast, is made from the more easily accessible silica.

As a result of bauxite mining's environmental toll, manufacturing a 12-ounce aluminum can is twice as energy-intensive as making a similarly sized glass bottle: 2.07 kilowatt hours of electricity for the can vs. 1.09 kilowatt hours for the bottle.

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But those figures assume that the materials used in the containers are 100 percent virgin—that is, entirely lacking in recycled content. The average beer can contains 40 percent recycled aluminum, while American beer bottles are typically composed of 20 percent to 30 percent recycled glass. But the energy savings that accumulate when you recycle a ton of aluminum are far greater than they are for glass—96 percent vs. a mere 26.5 percent. So if your brewery uses cans that contain lots of secondhand aluminum, the bottle's environmental edge narrows considerably.

That edge vanishes if your beer is trucked across several states. Without its liquid payload, the average beer can weighs less than an ounce, while an empty bottle clocks in at close to 6 ounces. That disparity makes a real difference in terms of overall greenhouse-gas emissions, since heavier items require more fuel to transport. This intriguing breakdown, which relies on transport data compiled by Germany's Wuppertal Institute, claims that once a cross-country truck journey is factored into the equation, a bottle ends up emitting 20 percent more greenhouse gases than a can. (In this example, the hypothetical can is made from 100 percent virgin aluminum; the recycled content of the glass bottle is not specified, but the energy required to mine the necessary silica is included in the calculation.)

You can avoid this part of the environmental equation by drinking local beers, though you might want to check where those nearby breweries obtain their containers—it's alarmingly common for empty cans and bottles to travel hundreds of miles from manufacturer to bottling plant.

Regardless of the road miles involved, aluminum cans enjoy a more promising post-celebration fate. About 45 percent of cans are recycled, compared with around 25 percent of bottles. This is partly because consumers erroneously believe that bottles will biodegrade in landfills, so they toss them in with their regular trash. But there's also a weaker demand for the glass that does end up in the blue bags. While automakers and other manufacturers crave aluminum, 90 percent of recycled glass simply ends up going back into bottles and similar containers. And sorting facilities usually separate brown, green, and clear bottles from one another before processing, a laborious and pricey endeavor. It takes a lot of energy to rid green glass, in particular, of the metals (such as iron and copper) that are used to tint it, and there's little market for the stuff once it's been recycled; as a result, a lot of towns don't even bother to recycle your Heineken empties.

Glass bottles would make more environmental sense if they were refillable, as they are in parts of Europe and Canada. Yes, there are energy costs associated with trucking the empty bottles back to the brewery. But according to a 2001 study conducted on behalf of the European Commission, refillables still come out ahead of single-use bottles and cans. In fact, if we assume that a refillable bottle were used 20 times, and that the glass bottles used over that period were recycled at a rate of 42 percent, then the refillable would win over disposable options as long as the distance between the brewery and the local distribution center was less than 2,608 miles. (As myriad beverage-industry professionals have pointed out, refillable bottles would be even more efficient if they were made of polyethylene terephthalate rather than glass.)

In lieu of waiting around (probably forever) for American brewers to adopt refillable bottles en masse, how about taking a pulled pint instead? Draught beer is the greenest means of getting your hops-and-barley fix, as kegs can last between 15 and 20 years. Sure, they're heavy, but in terms of packaging per serving they're actually lighter than glass bottles—based on an empty weight of 29.7 pounds, a 15.5-gallon keg provides just 2.88 ounces of packaging per 12-ounce beer.

While you're preparing to get smashed, also give some thought to how your beer is created. Brewing requires a lot of energy, especially during the heat-intensive wort-boil phase. Beer makers have begun taking steps to reduce their environmental impact: New York's Brooklyn Brewery, for example, uses wind-generated electricity to power all of its operations.

Ah, but is wind power all it's cracked up to be? That's fodder for a future column—until then, enjoy toasting the man who apocryphally drove the snakes out of Ireland, and take comfort in the fact that puke is fully biodegradable.

Is there an environmental quandary that's been keeping you up at night? Send it to ask.the.lantern@gmail.com, and check this space every Tuesday.

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